A crow-sized dinosaur from La Buitrera<\/h2>\n\n\n\n
The fossil was found at La Buitrera in Argentina\u2019s R\u00edo Negro Province, a site known for preserving small animals from the Cretaceous, late in dinosaur history. <\/p>\n\n\n\n
Read More: Scientists have found 6,000 cubic kilometers of magma beneath Tuscany, a Yellowstone-scale reservoir hidden under one of Europe\u2019s calmest-looking landscapes<\/a><\/h3>\n<\/div>\n<\/div><\/div>\n<\/div>\n\n\n\nThe dinosaur was about the size of a crow<\/a>, roughly 28 inches long and around 1.5 pounds, and coauthor Sebasti\u00e1n Apestegu\u00eda of the F\u00e9lix de Azara Foundation and Argentina\u2019s National Scientific and Technical Research Council known as CONICET<\/a> said it shows \u201cit was not a time of giants, but rather a time of immense biodiversity.\u201d<\/p>\n\n\n\nIt was discovered in 2014 and spent years being carefully prepared, piece by piece, because the bones are thin and fragile. Many bones were preserved close to their life position, which hints that the body was buried quickly, likely under shifting sand.<\/p>\n\n\n\n
This matters because most fossils of this group are incomplete, like getting a novel with half the pages missing. With a more complete body to compare, researchers can be more confident about what belongs where.<\/p>\n\n\n\n
Meet the alvarezsaurs<\/h2>\n\n\n\n
Alvarezsaurs are theropods, the dinosaur group that includes famous predators<\/a> and, eventually, modern birds. They are known for bird-like features, short arms that can end in a single oversized claw, and teeth that become very small in many later species.<\/p>\n\n\n\nFor decades, the alvarezsaurs story looked lopsided. Many of the best fossils came from Asia, while finds in South America were often fragmentary, making it hard to tell whether the animals evolved in one place and spread, or were widespread early on.<\/p>\n\n\n\n
Back in 2012, Alnashetri<\/em> was first formally described from only a few leg bones from the same Patagonian region. That earlier description set the name, but it could not fully explain the animal\u2019s place in the wider family tree.<\/p>\n\n\n\nA \u201cRosetta Stone\u201d skeleton<\/h2>\n\n\n\n
The new study was co-led by the University of Minnesota Twin Cities, and the team describes the fossil as a \u201cmissing link\u201d for a group that has been hard to pin down. <\/p>\n\n\n\n
Paleontologist Peter Makovicky called the leap from scraps to a near-complete skeleton \u201clike finding a paleontological Rosetta Stone,\u201d and he said it gives researchers a much-needed reference point for identifying other partial fossils and tracking changes in body size and anatomy over time.<\/p>\n\n\n\n![\"A](\"https:\/\/www.ecoticias.com\/en\/wp-content\/uploads\/2026\/04\/tiny-dinosaur-fossil-patagonia-alnashetri-skeleton-1.jpg\" "\\"\\"")
The discovery of a nearly complete Alnashetri cerropoliciensis skeleton in Patagonia serves as a “Rosetta Stone” for understanding the evolution of a bizarre, bird-like dinosaur lineage.<\/figcaption><\/figure>\n\n\n\nScientists also looked closely at the bones themselves, using microscopic clues<\/a> to estimate age. Those patterns suggested the animal was an adult at about four years old, which helps avoid mistaking youthful features for brand-new species.<\/p>\n\n\n\n\n\n\nRead More: A potentially habitable super-Earth has been discovered just 10 light years away, and the big question of what might be waiting for us out there returns with a vengeance<\/a><\/h3>\n<\/div>\n<\/div><\/div>\n<\/div>\n\n\n\nIn practical terms, that matters a lot. If you compare a teenage dog to a full-grown dog, you might think they are different breeds unless you know their ages.<\/p>\n\n\n\n
Small first, specialized later<\/h2>\n\n\n\n
One of the clearest takeaways is that Alnashetri<\/em> was small without being as \u201cextreme\u201d as its later relatives. It lacked some of the most reduced hand features seen in later alvarezsaurs, and its teeth were not as tiny, even though the animal was already petite. <\/p>\n\n\n\nThat fits with the idea that very small body sizes may have evolved more than once within this lineage.<\/p>\n\n\n\n
That pattern supports a simple idea. In this lineage, getting small seems to have happened before the full set of specialized traits, including the digging-style forelimbs and other changes often linked to feeding on social insects such as ants and termites.<\/p>\n\n\n\n
Not everyone has agreed on how that shrinking happened. A 2021 Current Biology<\/em> study<\/a> argued that body size in alvarezsauroids, the broader branch that includes alvarezsaurs, dropped quickly between about 110 million and 85 million years ago, and that growth patterns varied across the group.<\/p>\n\n\n\nA world tour without ocean crossings<\/h2>\n\n\n\n
The team did not stop with Patagonia. By revisiting older fossils in museum collections from North America and Europe, they recognized additional alvarezsauroid specimens, which pushes the group\u2019s reach beyond the places where it is usually discussed.<\/p>\n\n\n\n
To explain that spread, the researchers point to Pangea, the ancient supercontinent that once connected much of Earth\u2019s land. In the paper published February 25, 2026, they argue that as Pangea broke apart over tens of millions of years, populations could have been separated as the continents drifted, rather than needing unlikely ocean crossings.<\/p>\n\n\n\n
\n\n\nRead More: After 500 years, they believe they have found the key that could solve one of the greatest mysteries of the Vitruvian Man, Leonardo\u2019s most famous and enigmatic drawing.<\/a><\/h3>\n<\/div>\n<\/div><\/div>\n<\/div>\n\n\n\nIt is a bit like tearing a big map into smaller pieces and watching each piece drift away. The animals did not have to cross the gaps that opened later, because the gaps were not there yet.<\/p>\n\n\n\n
Why this tiny dinosaur matters now<\/h2>\n\n\n\n
Tiny fossils can end up doing outsized work in science. With a nearly complete skeleton, researchers can test old ideas about evolution that were built on scraps, and they can do it without guessing what is missing.<\/p>\n\n\n\n
It also changes what a \u201cdinosaur landscape<\/a>\u201d looks like in your head. If you picture only giants, you miss most of the action, and this find puts smaller hunters back into the scene.<\/p>\n\n\n\nResearchers plan to keep studying fossils from the same area, so this story may keep changing as new bones come to light. For now, Alnashetri<\/em> is a reminder that big discoveries do not always come from big animals.<\/p>\n\n\n\nThe main study has been published in Nature<\/em><\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"How small can a dinosaur be and still shake up what scientists think they know? A newly described fossil from … <\/p>\n
It was discovered in 2014 and spent years being carefully prepared, piece by piece, because the bones are thin and fragile. Many bones were preserved close to their life position, which hints that the body was buried quickly, likely under shifting sand.<\/p>\n\n\n\n
This matters because most fossils of this group are incomplete, like getting a novel with half the pages missing. With a more complete body to compare, researchers can be more confident about what belongs where.<\/p>\n\n\n\n
Meet the alvarezsaurs<\/h2>\n\n\n\n
Alvarezsaurs are theropods, the dinosaur group that includes famous predators<\/a> and, eventually, modern birds. They are known for bird-like features, short arms that can end in a single oversized claw, and teeth that become very small in many later species.<\/p>\n\n\n\n For decades, the alvarezsaurs story looked lopsided. Many of the best fossils came from Asia, while finds in South America were often fragmentary, making it hard to tell whether the animals evolved in one place and spread, or were widespread early on.<\/p>\n\n\n\n Back in 2012, Alnashetri<\/em> was first formally described from only a few leg bones from the same Patagonian region. That earlier description set the name, but it could not fully explain the animal\u2019s place in the wider family tree.<\/p>\n\n\n\n The new study was co-led by the University of Minnesota Twin Cities, and the team describes the fossil as a \u201cmissing link\u201d for a group that has been hard to pin down. <\/p>\n\n\n\n Paleontologist Peter Makovicky called the leap from scraps to a near-complete skeleton \u201clike finding a paleontological Rosetta Stone,\u201d and he said it gives researchers a much-needed reference point for identifying other partial fossils and tracking changes in body size and anatomy over time.<\/p>\n\n\n\n Scientists also looked closely at the bones themselves, using microscopic clues<\/a> to estimate age. Those patterns suggested the animal was an adult at about four years old, which helps avoid mistaking youthful features for brand-new species.<\/p>\n\n\n\n In practical terms, that matters a lot. If you compare a teenage dog to a full-grown dog, you might think they are different breeds unless you know their ages.<\/p>\n\n\n\n One of the clearest takeaways is that Alnashetri<\/em> was small without being as \u201cextreme\u201d as its later relatives. It lacked some of the most reduced hand features seen in later alvarezsaurs, and its teeth were not as tiny, even though the animal was already petite. <\/p>\n\n\n\n That fits with the idea that very small body sizes may have evolved more than once within this lineage.<\/p>\n\n\n\n That pattern supports a simple idea. In this lineage, getting small seems to have happened before the full set of specialized traits, including the digging-style forelimbs and other changes often linked to feeding on social insects such as ants and termites.<\/p>\n\n\n\n Not everyone has agreed on how that shrinking happened. A 2021 Current Biology<\/em> study<\/a> argued that body size in alvarezsauroids, the broader branch that includes alvarezsaurs, dropped quickly between about 110 million and 85 million years ago, and that growth patterns varied across the group.<\/p>\n\n\n\n The team did not stop with Patagonia. By revisiting older fossils in museum collections from North America and Europe, they recognized additional alvarezsauroid specimens, which pushes the group\u2019s reach beyond the places where it is usually discussed.<\/p>\n\n\n\n To explain that spread, the researchers point to Pangea, the ancient supercontinent that once connected much of Earth\u2019s land. In the paper published February 25, 2026, they argue that as Pangea broke apart over tens of millions of years, populations could have been separated as the continents drifted, rather than needing unlikely ocean crossings.<\/p>\n\n\n\n It is a bit like tearing a big map into smaller pieces and watching each piece drift away. The animals did not have to cross the gaps that opened later, because the gaps were not there yet.<\/p>\n\n\n\n Tiny fossils can end up doing outsized work in science. With a nearly complete skeleton, researchers can test old ideas about evolution that were built on scraps, and they can do it without guessing what is missing.<\/p>\n\n\n\n It also changes what a \u201cdinosaur landscape<\/a>\u201d looks like in your head. If you picture only giants, you miss most of the action, and this find puts smaller hunters back into the scene.<\/p>\n\n\n\n Researchers plan to keep studying fossils from the same area, so this story may keep changing as new bones come to light. For now, Alnashetri<\/em> is a reminder that big discoveries do not always come from big animals.<\/p>\n\n\n\n The main study has been published in Nature<\/em><\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":" How small can a dinosaur be and still shake up what scientists think they know? A newly described fossil from … <\/p>\nA \u201cRosetta Stone\u201d skeleton<\/h2>\n\n\n\n
Read More: A potentially habitable super-Earth has been discovered just 10 light years away, and the big question of what might be waiting for us out there returns with a vengeance<\/a><\/h3>\n<\/div>\n<\/div><\/div>\n<\/div>\n\n\n\n
Small first, specialized later<\/h2>\n\n\n\n
A world tour without ocean crossings<\/h2>\n\n\n\n
Read More: After 500 years, they believe they have found the key that could solve one of the greatest mysteries of the Vitruvian Man, Leonardo\u2019s most famous and enigmatic drawing.<\/a><\/h3>\n<\/div>\n<\/div><\/div>\n<\/div>\n\n\n\n
Why this tiny dinosaur matters now<\/h2>\n\n\n\n